Ram apparatus with fast acting valve construction



Dec. 13, 1966 F. D. EZEKIEL 3,293,000

RAM APPARATUS WITH FAST ACTING VALVE CONSTRUCTION Filed Nov. 17, 1964 my ,0. Z ifQ/CQ United States Patent 3,291,000 RAM APPARATUS WITH FAST ACTING VALVE CONSTRUCTION Frederick D. Ezekiel, 73 Temple Road, Waltham, Mass. Filed Nov. 17, 1964, Ser. No. 411,913 3 Claims. (Cl. 91-165) This invention relates to a method and apparatus for controlling a flow of fluid energy and applying the controlled flow to perform useful work on a body. In one specific instance the invention is concerned with a method of instantaneously transferring fluid energy from one member to another.

In devices heretofore used for such purposes the necessity for incorporating in the device a conduit path and valve through which controlled fluid energy must pass results in a time lag. When a demand for extremely fast energy transfer is necessary as in simulation of explosions or high impact forces, shocks and the like, the existence of the time lag noted above constitutes an undesirable limitation on the response characteristics of the system.

It is, therefore, a chief object of the invention to devise an improved apparatus and method for high speed load application to specimens, diaphragms and other stress responsive bodies.

Another object of the invention is to devise an apparatus of the class described in which the path of travel of controlled fluid energy is greatly minimized to a point where little if any time lag is present.

With these objectives in mind specifically, I have conceived of a novel form of apparatus in which a ram structure is combined with a valve means located directly in the ram with the result that energy flow takes place through a very short distance of travel.

The nature of the invention and its other objects and novel features will be more fully understood and appreciated from the following description of a preferred embodiment selected for purposes of illustration and shown in the accompanying drawings in which:

The figure shown in the drawings is a view in cross section taken vertically through the ram apparatus of the invention.

The apparatus of the invention in general comprises a source of stored fluid energy, an energy body which re sponds to the source of fluid energy to convert said en-* ergy to useful work, and means consisting of a movable control element for transferring the stored energy to the energy receiving body.

Considering in detail the structure shown in the drawing, numeral 2 denotes an accumulator body in which is formed a chamber 4 for receiving pressurized fluid to constitute a source of stored energy. Numeral 6 denotes a passageway through which a fluid may be forced into the chamber 4 under pressure from a supply source 8 controlled by a valve 10.

The accumulator body may, in one desired form, be solidly secured to the underside of a horizontal support 12 by means of holding members 14 and 16. The lower section of member 2 is formed with a recess 18 in which is located an energy receiving ram body 20 preferably of a cylindrical shape and provided with sealing rings 22 and 24. The energy receiving ram body 20' has a lower reduced section 20a which is spaced from adjacent inner surface of the member 2 to provide an annular volume V into which a supply of backing fluid is furnished from a source 28 through inlets 30 and 32.

The supply of backing fluid is conducted through ducts 34 and 36 into a space 38 which is defined at one side by the bottom of a movable control valve element 40. Backing fluid pressure is thereby exerted against the hot- "ice tom 39 of the control valve 40 to maintain an upper conical portion 40a thereof in sealing engagement with a seating portion 42 formed in member 2.

The pressure of backing fluid against the member 40 can be selectively relieved by a trigger valve 44 when desired. It is pointed out that the backing fluid pressure normally holds the valve member 40 as well as the ram member 20 in the raised position shown in the drawing. However, with release of pressure by opening the trigger valve 44, flow of energy takes place in chamber 4 and the valve 40 moves downwardly into space 38 transferring energy almost instantaneously to the ram member 20 which in turn is impacted against a test specimen 50 supported on a suitable base.

Thus it will be apparent that an extremely high load force may be exerted in a very small time interval by reason of the novel arrangement of the transfer valve 40 being located directly in the ram body 20 to which fluid energy is to be delivered.

As an example of one typical fast acting valve of the invention there may be cited an arrangement in which the area of valve member 40 resisting the accumulator pressure is one square inch, while the area exposed to backing fluid pressure may be ten square inches. Thus the backing fluid pressure must be at least one-tenth the accumulator pressure.

A unique feature of the arrangement described is the provision of means for relieving the backing pressure from exerting a force on the specimens prior to a test. This is accomplished by forming the ram member 20 with a recessed bottom section 20a so that there is provided a small land surface all the way around the structure as indicated at 52. The dimensions of the several parts may then be chosen to hydraulically balance the ram.

The upper ram area may, for example, be about square inches. With this area a peak pressure of 10,000 p.s.i. is required to develop a load of 1,500,000 pounds.

It will be understood that I may desire to include in the member 2 a suitable release valve for discharging the accumulator pressure when desired and I may also desire to utilize a variable valve arrangement for the purpose of controlling the time delay between the opening and the pressurizing valve, and the opening of the release valve noted.

While I have described and illustrated a preferred embodiment of the invention, it should be understood that various changes and modifications may be resorted to Within the scope of the appended claims.

I claim:

1. An apparatus of the class described comprising an accumulator having a source of stored fluid energy therein, a ram member located in the lower end of the accumulator for receiving fluid energy from the accumulator and applying said energy to a specimen to be stressed, valve means mounted between the accumulator and the ram member for controlling flow of fluid energy from the accumulator to the ram, said valve member being mounted within the confines of a recessed portion of the ram, means for exerting a backing fluid pressure through the ram and against one side of the valve means to hold it in a closed position and means for pressurizing the source of stored fluid energy.

2. A structure according to claim 1 including trigger valve means for releasing locking fluid pressure.

3. An apparatus of the class described comprising an accumulator having a source of stored fluid energy therein, a ram member located in the lower end of the accumulator for receiving fluid energy from the accumulator and applying said energy to a specimen to be stressed, valve means mounted between the accumulator and the ram member for controlling flow of fluid energy from the accumulator to the ram, said valve member being mounted within the confines of a recessed portion of the ram, means for exerting a backing fluid pressure through the ram and against one side of the valve means to hold it in a closed position and means for pressurizing the source of stored fiuid energy, trigger valve means for releasing locking fluid pressure, said ram member being recessed at an underside thereof to form a land surface against which pressure may be exerted, said surface being related to a surface of the valve means to provide for a hydraulic balance between the valve member and the ram.

References Cited by the Examiner UNITED STATES PATENTS MARTIN P. SCHWADRON, Primary Examiner.

P. T. COBRIN, P. E. MASLOUSKY,

Assistant Examiners. 

1. AN APPARATUS OF THE CLASS DESCRIBED COMPRISING AN ACCUMULATOR HAVING A SOURCE OF STORED FLUID ENERGY THEREIN, A RAM MEMBER LOCATED IN THE LOWER END OF THE ACCUMULATOR FOR RECEIVING FLUID ENERGY FROM THE ACCUMULATOR AND APPLYING SAID ENERGY TO A SPECIMEN TO BE STRESSED, VALVE MEANS MOUNTED BETWEEN THE ACCUMULATOR AND THE RAM MEMBER FOR CONTROLLING FLOW OF FLUID ENERGY FROM THE ACCUMULATOR TO THE RAM, SAID VALVE MEMBER BEING MOUNTED WITHIN THE CONFINES OF A RECESSED PORTION OF THE RAM, MEANS FOR EXERTING A BACKING FLUID PRESSURE THROUGH THE RAM AND AGAINST ONE SIDE OF THE VALVE MEANS TO HOLD IT IN A CLOSED POSITION AND MEANS FOR PRESSURIZING THE SOURCE OF STORED FLUID ENERGY. 